1. Field of the Invention
This invention relates to a process for the production of reaction products of epoxidized ricinoleic acid glycerides with sulfur trioxide. The products prepared in accordance with the invention show surface-active properties and may be used as emulsifiers and as constituents of detergents.
2. Statement of Related Art
Functional groups may be introduced into a molecule of unsaturated fatty acid esters using known methods such as by conversion of the olefinic double bonds of these compounds into an oxirane ring by epoxidation, followed by opening of the oxirane ring with nucleophiles to form 2-hydroxyalkyl derivatives.
It is also known that epoxides may be converted into 1,2-glycol sulfates by reaction with sulfur trioxide. In the case of ethylene oxide, however, this reaction is so violent according to J. Org. Chem. 25, 864 (1960) that the direct reaction with sulfur trioxide is accompanied by decomposition. The reference indicates that only the reaction with a sulfur trioxide/dioxide adduct leads to the desired glycol sulfate. German Patent Document DE-AS 20 40 503 discloses first reacting the epoxide with sulfur dioxide to form the glycol sulfite followed by further reaction with sulfur trioxide to form the glycol sulfate.
An important species of the above-mentioned reaction products of epoxy fatty acid esters with sulfur trioxide is that obtained using epoxidized castor oil as the epoxy reactant. This compound is prepared by sulfatization of epoxidized castor oil with oleum. However, this process generates by-products having a high salt content which is undesirable from the environmental wastewater standpoint. In addition, the products obtained by this process contain a considerable concentration of sulfate which can be very corrosive. Similar disadvantages attend sulfonation processes which use sulfuric acid or chlorosulfonic acid. Such processes, and the above mentioned oleum sulfonation process, are described in Kirk-Othmer, Encyclopedia of Chemical Technology, 2nd Edition, Vol. 19, pages 301 to 306, J. Wiley & Sons, New York, 1983 and in Winnacker-Kuechler, Chemische Technologie, 4th Edition, Vol. 4, pages 464 to 468, Carl Hanser Verlag, Munchen, 1984.